It is important first to stipulate that the field called cinematographic postproduction operates according to two resolutions, respectively the resolution called 2K, meaning in theory 2048×1556 pixels, and 4K also meaning in theory 4096×3112 pixels.
The earliest technology used to make “digital intermediate” films concerns the cathode ray tube (CRT). This technology therefore uses a spot issuing from a cathode ray tube which carries the image to be exposed on the film photoresist.
The accuracy of the spot is conditioned in particular by its energy. In fact, for a high resolution, a low energy spot should be employed, so that the productivity/modulation transfer function ratio, that is, the percentage of spatial data of the starting image that is really transferred to the film support according to the resolution, is mediocre. Furthermore, the geometrical accuracy, the emission spectrum and the purity of the phosphorus layer with which the inside of the tube is coated, require very high quality cathode ray tubes, which are relatively costly, and have a limited service life because the properties of the phosphorus change during its use.
This technology is therefore particularly restrictive in terms of upkeep and maintenance.
The laser technology is also known. This is based on the scanning of a moving object film by three laser beams issuing from solid or gas lasers (for the colors blue and green) and a laser diode (for the color red).
While the resolutions in 2K and 4K can be obtained with this technology, the productivity is however not always adequate, particularly for obtaining a cinemascope film format.
Moreover, the application of the laser technology, particularly the blue laser, is costly in terms of maintenance. In addition, the service life of the lasers is limited.
Finally, the application of the laser implies a film supply system during exposure, synchronized to the nearest fraction of a micron, which is complex and costly to achieve.
The need has therefore arisen to develop a system for making and producing motion picture films from digital images, which can reach a resolution of 2K and 4K, with high production rates, high contrast quality, and reduced operating and maintenance costs.
This is the object of the present invention.